On 1/31/07, Fernando Perez <fperez.net@gmail.com> wrote:
> On 1/31/07, Travis Oliphant <oliphant@ee.byu.edu> wrote:
> > Fernando Perez wrote:
>> > I don't know. If you have other things pointing to it, should you
> > really close it?
>> Well, it's like a file: you can close it because you've decided it's
> time to close it, and I think it's better that other references get an
> exception if they try to write to it when they shouldn't:
>> In [2]: file1 = open('foo','w')
>> In [3]: file1.write('Some text')
>> In [4]: file2 = file1
>> In [5]: file1.close()
>> In [6]: file2.write("I'm not the original owner but I'll try to write anyway")
> ---------------------------------------------------------------------------
> exceptions.ValueError Traceback (most
> recent call last)
>> /home/fperez/<ipython console>
>> ValueError: I/O operation on closed file
>>> This seems like the right API to me.
>> > At any rate you have access to the mmap file through the _mmap
> > attribute. So, you can always do
> >
> > self._mmap.close()
>> I don't like an API that encourages access to internal semi-private
> members, and it seems to me that closing the object is a reasonably
> top-level operation whose impmlementation details (in this case the
> existence and name of the _mmap member) should be encapsulated out.
>> Cheers,
>> f
After asking this question rather for acedemical reasons, I now
realize that I indead must have a "somehow dangling" (i.e. not
deleted) reference problem.
I create my Medical-Image-File-class object on a 400MB file repeatedly
(throwing the result away) and after 5 calles I get:
File "/jws30/haase/PrLinN/Priithon/Mrc.py", line 55, in __init__
self.m = N.memmap(path, mode=mode)
File "/home/haase/qqq/lib/python/numpy/core/memmap.py", line 67, in __new__
mm = mmap.mmap(fid.fileno(), bytes, access=acc)
EnvironmentError: [Errno 12] Cannot allocate memory
Calling gc.collect() seams to clean things up and I can create 4-5
times afterwards, before running out of memory space again.
Note: My code is based on code that was tested and worked using numarray.
Thanks,
Sebastian